Clinical Trial of Two 6% Hydrogen Peroxide Equivalent Whitening Systems: Strips Versus Paint-On

Objective: The new, peroxide-containing tooth whitening systems use various devices to deliver peroxide to the tooth surface. This 14-day clinical trial was conducted to evaluate the clinical effectiveness of a new paint-on system relative to a marketed control having a similar pre-treatment peroxide concentration. Methods: A total of 30 healthy adults were randomized to Colgate® Simply White^TM, an 18% carbamide peroxide paint-on liquid in an applicator bottle, or Crest® Whitestrips®, a 6.0% hydrogen peroxide gel on a whitening strip. Study participants were supplied with the manufacturers written instructions for use, treatment was twice daily for 30 minutes, and all usage was unsupervised. Efficacy was measured as L*a*b* color change using digital images of the anterior dentition. Results: Adjusting for baseline, the Day 14 estimated means and standard errors for Db* (yellowness) were –0.20 (0.29) for the paint-on group compared to –2.57 (0.31) for the strip group. Response was similar for lightness/brightness (DL*), with the adjusted mean (SD) of 0.12 (0.26) and 1.71 (0.27) in the paint-on and strip groups, respectively. Only the strip group differed significantly (p < 0.0001) from baseline for Db* or DL*. Between-group comparisons showed highly significant (p < 0.001) greater color improvement for the strip group for all of the individual parameters (Db*, DL*, Da*), as well as composite color (DE*) and overall whiteness (DW*). Both treatments were well tolerated, and no subjects discontinued treatment early due to an adverse event. Conclusion: Use of the 6.0% whitening strips resulted in more than ten-fold superior whitening to the 18% carbamide peroxide paint-on liquid, the latter of which failed to exhibit any significant L*a*b* color change from baseline.